kartoo uses a Flash interface to show their search results, its especially useful when seeing how sites relate to each other, and easily narrow the search just by point and click.
According to the FAQ at Kartoo.com, they use a number of search engines (in other words, they are a metacrawler/meta search engine). They seem to rely heavily on Google, at least it seems that way from the searches I have tested there.
They have a desktop version of their search in development, I think Kartoo might very well be a very nice search application, right now I feel they still have issues to iron out with their user interface.
A couple of articles about kartoo, if you want to know more:
Web sites identified by a search are placed on a map; the sites are represented by balls, with their size in proportion to how relevant they are. The balls are connected together by dynamic semantic links (e.g. the semantic link between daewoo.com and renault.fr is